Business Segments (Tables)

3 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Business Segments [Table Text Block]

	Three Months Ended
	March 31,
	2021	2020
Millions
Operating Revenue
Regulated Operations
Residential	$45.6	$40.9
Commercial	39.7	37.3
Municipal	12.6	10.3
Industrial	129.0	118.8
Other Power Suppliers	38.4	38.3
Other	27.7	19.7
Total Regulated Operations	293.0	265.3
ALLETE Clean Energy
Long-term PSA	18.1	17.3
Other	2.8	2.8
Total ALLETE Clean Energy	20.9	20.1
Corporate and Other
Long-term Contract	21.7	22.4
Other	3.6	3.8
Total Corporate and Other	25.3	26.2
Total Operating Revenue	$339.2	$311.6
Net Income (Loss) Attributable to ALLETE
Regulated Operations	$45.0	$57.5
ALLETE Clean Energy	7.4	11.7
Corporate and Other	(0.6)	(2.9)
Total Net Income Attributable to ALLETE	$51.8	$66.3

NOTE 10. BUSINESS SEGMENTS (Continued)

	March 31, 2021	December 31, 2020
Millions
Assets
Regulated Operations	$4,184.1	$4,196.8
ALLETE Clean Energy	1,596.6	1,483.3
Corporate and Other	493.8	404.5
Total Assets	$6,274.5	$6,084.6